Where can i find the source? (change the hdmi to another hdmi with Rapsberry Pi)

Hi everyone, i need help you all to give me the where can i find the source about my project. I need to connect the raspberry Pi 3 to the hdmi switcher. so i can change the from hdmi to another hdmi. what i know, the connection of them need to be used by RS323. In the raspberry pi , i will create the code using the Python programming language. To change the hdmi to another hdmi is used the remote. it mean it used the IR signal to change them. So, may i know where can i get the signal HDMI switcher??